My friend loves opening different trades at a time, most at times is difficult for him to control what's should be. Trading on free chart with multiple opening can be very dangerous. Yesterday he experience unusual hit when bitcoin price drops again, four trades loss at once when the market go against him. Personally I don't advise multiple trade especially when you're not familiar with trade
I find it very difficult to keep track of many coins, it is even more difficult to trade all of them, especially if you are at an early stage. If you have the desire and confidence that you will be able to control everything qualitatively, then try, but remember the importance of using stop loss. When there is a rapid fall, then you simply will not have time to exit all trades without losses, and this happens quite often. After several such mistakes, your friend may simply not have a trading deposit left.
Tracking them is easier when you use a portfolio app. I have one of them and I even connected it to my account in a way, it doesn't have any right to do anything but just read. This means that it can follow how much profit I made or how much loss I have.
This is how I keep track of it because anytime something goes down 5%, it sends me a notification and when that happens I take a look at it and make a decision. Either I sell it and get out, or I will keep holding it, and rarely even buy more if it is bitcoin because I love it when bitcoin price goes down, it means I can buy more when it is cheap. Long story short there are ways to trade 20+ different coins if you want, as long as you are willing to be a bit more careful about what you use to do that.